Chapter 10 - SOLID-GAS PROCESSES

Abstract

This chapter discusses the solid–gas processes to demonstrate the potential for using IS. It also discusses the solid–gas processes that involve mixing, size reduction, particle-size classification, calcination of phosphate, production of pigments, roasting of ores, plasma-jet processes as well as dust collection, and granulation. A physical-mathematical granulation model has been established for the process of dust collection in the presence of granulation in coaxial IS. A modified model can be applied also to other kinds of flows. The model assumes granulation between small and large particles and the probability of interparticle collisions. It is possible to predict by the model the conditions for only countercurrent flow of the small particles in regard to the large particles or, simultaneously, counter- and co-current flows. As the model assumes that the mass ratio mL/mS >20, it follows that for satisfactory granulation the diameter ratio dL/dS between the large and the small particles should be greater than 2.7. The parameter of the model is the adhesion coefficient, φ. The coefficient defined by equation must be established experimentally and has been found to depend only on air velocity at the inlet pipes to the granulator. The model also enables one to predict the composition of the dust product from the composition of the feed and the operating conditions of the granulator.